The Kangers and Kayfuns fit fine with the top cap (beauty ring) on there. I use a Kayfun most of the time on mine.
The thing to watch out for with the Evic is screwing the atomizer down too tight. After pressing my center post down too far, I finally got it fixed with the "#60 O ring" fix, and now things are working again. Now I'm careful to just screw my Kayfun until it shows "atomizer detecting" on the screen, then gently unscrew the top cap until it's tight against the bottom of the Kayfun (or Kanger).